Dr. Barry Logan, a leading toxicologist, says that labs are only able to test for about 17 out of a possible 100 chemical compounds used to craft synthetic marijuana. It's almost as difficult to detect bath salts, as toxicology labs can only test for 40 out of 100. Logan added that as soon as they're able to test for a new compound, something different is created, leaving them always a step behind.

One of the reasons that designer drugs like synthetic marijuana and bath salts have become so popular is that they can be obtained legally and cannot be detected by the average drug test. As for Eugene's attack, Logan remarked that his behavior was "consistent with bath salts." We've heard of "killer weed," but no common strain gives you the munchies for human flesh.